If you are a seller who needs to close a sale as quickly as possible, then you should know that getting the highest price possible is not one of your priorities. It does not mean that you won't or cannot get the highest price, but it means that the price is not the deciding factor. A buyer who can give you a quick closing time will appeal much more to you than a buyer who can offer you more money but the negotiation and closing time drag on.
It's always good to know how low you will go, in terms of selling price. This will help to eliminate some of the offers that you find simply offensive or ridiculous. Even though you should consider all offers seriously and take into consideration the terms of each offer, sometimes, if you know the bottom line and are strict about it, you can save yourself time.
Once you know what your limits and reasons are, discuss them with your agent so that they can help you set your goals realistically. If you decide to list your home on your own, make sure you do research on the current market, and you get the proper advice you need in terms of legal issues, etc. The key is to be realistic and to know what your goals are so that they can be met.